The invention relates to synchronizing a first high data-rate radio transceiver and a second high data-rate radio transceiver, and in particular to synchronizing ultra-wideband (UWB) radio transceivers. Further, the invention relates to a radio device comprising a high data-rate radio transceiver adapted to be synchronized with an external high data-rate radio transceiver.
Portable electronic devices such as mobile telephones, photo cameras, displays etc. need to transfer increasingly large quantities of data to and from other devices. Well-known examples for large quantities of data are digital photographs, film sequences or audio files to be downloaded from or transmitted to a computer or shared with other users. A wireless transfer of such data, besides other advantages, avoids the need for adequate cables. However, from the user's view point, any advanced cable replacement technology for portable electronic devices has to comply with the requirements of quick data transfer (preferably as quick as the equivalent wired interface) and low power consumption.
An existing wireless technology with broad penetration in portable electronic devices is the Bluethooth (BT) standard. BT is able to discover efficiently other devices and to transfer data in a power saving manner, with the maximum current consumption from the transceiver being typically only tens of milliamperes. However, the maximum data-rate of about 3 Mbps (megabit per second) is lower than that required by many applications and, thus, can not replace wire interfaces operating at higher data-rates—e.g. USB 2.0 (universal serial bus) operating at 480 Mbps. Further, the energy per bit transferred in BT is high.
UWB, as an example, better meets the requirements for high data-rates and low energy per bit transferred. UWB provides for raw data-rates comparable to wire interfaces as, for example, USB 2.0, and energy efficiency per bit that is an order of magnitude better than BT. Nevertheless, the current consumption of such high data-rate radio transceivers, owing to the high data transfer rates, can reach up to one ampere. Therefore, such high data-rate radio transceivers have a high power consumption during active states.
It has been proposed to combine a high data-rate radio transceiver (e.g. UWB transceiver) and a lower data-rate radio transceiver (e.g. BT transceiver) to combine lower data-rate (e.g. BT) connectivity with high data-rate (e.g. UWB) pipelining. This allows to use the lower data-rate radio transceiver to support control functions of the high data-rate radio transceiver.